Android Compatibility: a Primer for iOS Developers

I’ve been developing iOS apps since the end of 2010, so have only ever seen the world of Android from a distance. Where I’m from, you hear a lot of talk about the problem of fragmentation on Android. Whereas the adoption stats for new versions of iOS are pretty impressive (apparently iOS7 hit 33% iOS market share in just 24 hours, and 58% after one week) the situation on Android looks very different, with the second most popular Android version remaining Gingerbread, released in 2010.

With my iOS hat on, when PrayerMate launched on Android earlier this year, I assumed it would be far too much hassle for one independent developer working in his spare time to take on this fragmentation issue, so I decided to support only Honeycomb upwards – a major OS update which introduced some significant new changes to the core Android UI.

But what they don’t tell you over in iOS developer world is that the Android ecosystem provides some pretty impressive tools to make supporting older Android versions really easy. Let me give you a quick overview of just three reasons why adding support for older phones isn’t nearly as hard as you might imagine:

1. Compatibility-aware compiler

When you set up your Android project (I use Eclipse) you specify the minimum version your app supports. Out of the box, the compiler knows exactly which API level each feature was introduced at, and will throw a compiler error if you try to use functions that are too modern for the versions you claim to support. If you use conditional statements to alter behaviour by Android version, then you can use attributes in your code to say what API level a given function is designed to run against, to disable these compiler errors on just those bits of code. It also warns about deprecated APIs so that you can use more modern alternatives where appropriate.

This makes the situation so much easier than the native state-of-affairs on iOS. It wouldn’t surprise me if there was some way to figure out how to make XCode throw such compatibility errors, but out of the box you get no warning whatsoever if you use functions introduced in an iOS version later than the minimum one you hope to support, and the only way to discover this is through thorough testing and waiting for the crashes to happen (which needless to say is not very scalable!)

2. Compatibility support libraries

Another seriously impressive feature of the Android SDK is the compatibility support libraries. In many situations, where a new API has been introduced, the SDK then goes and adds an alternative implementation that conforms to the same method signatures but which ports the new functionality back so that it also works on older OS versions. This avoids the need to have lots and lots of conditional branches running separate codepaths on separate Android versions, and instead means you can just write one lot of code that works everywhere.

3. ActionBarSherlock

Ok, so this one isn’t native to the Android SDK (although a very similar library is) but there’s a great open source project out there called ActionBarSherlock which lets you add the “action bar” UI paradigm introduced in Honeycomb even when running on older Android versions. It requires a minimal amount of setup, and works almost identically to the real action bar. So, again, rather than having to invent two separate user interfaces depending on the Android version, you can have the same functionality running everywhere.


In conclusion, the Android fragmentation problem doesn’t seem nearly so scary to me as it once did. I managed to get PrayerMate to support Android versions all the way back to Froyo (v2.2) in a single (pretty relaxed) weekend, and because of support from the compiler I can be pretty confident of not having missed anything.

PrayerMate on older Android phones

144x144 I know that every time I release a new update to PrayerMate, I always say it’s the most exciting version ever. But today’s update to PrayerMate for Android makes me really extra excited!

New downloadable “Prayer gallery”

Firstly, it adds the downloadable prayer gallery that iOS users received earlier in the week. It’s very small for now, but it includes a small selection of Bible prayers (including the traditional form of the Lord’s Prayer that many of you have asked for) and some tips from OMF UK on how to pray for missionaries. You can download the prayers into PrayerMate, and then feel free to customise them, e.g. by inserting the personal names of your particular friends.

It also includes some extracts from a forthcoming book published by 10ofthose called “Water on the Word” by Andrew Case, designed to help husbands pray biblically for their wives. If you find these helpful, let me know, and I can add more to the gallery.

Support for older Android versions

Several of you expressed disappointment that PrayerMate wasn’t able to run on your particular phone, because it only supported the newer Android versions. I’m pleased to announce that as of today, it will now run on Android versions back to Froyo (v2.2.0). If you’re running a version of Android older than that then may I politely suggest that it’s really time you treated yourself to a new phone. I can’t necessarily promise that absolutely every feature will work perfectly, but the basics are all there and I can always release incremental fixes over time if you report specific problems to me.

Improved Dropbox support

As well as a little bug fix that was preventing Dropbox imports from updating your card details, you can now also import individual text files from your Dropbox folder. Add a “.txt” file to your “Apps/PrayerMate” Dropbox folder, fill it with the contents of your prayer, and you can then load that in as a subject.

Enter a list of names

One of the biggest factors that stops people getting started with PrayerMate is the challenge of actually setting up your prayer points. The new “create from list” feature aims to make this a little easier, by allowing you to enter a whole list of names, and PrayerMate will go away and create a subject for each one.

Download it today

If you’ve not got PrayerMate for Android already, you can download it on Google Play or on the Amazon App Store.

PrayerMate iOS v3.3.0

PrayerMate Logo 1Today there is a small yet important new update to PrayerMate for iOS. It addresses three very long-standing feature requests:

  1. It includes a new “prayer gallery” of downloadable content. This is very small and simple at the moment, but I can add it to gradually over time without requiring further app updates. It includes some links to various Bible prayers that you can copy and paste, and I’ll be sure to add many more over the coming weeks and months. If you have any prayers that you would like to share with other PrayerMate users, do hit the “Get in touch” button inside the app.
  2. Multiple reminder alarms. Where previously you could only have one reminder per day, you can now add as many as you like through the day. If you decide you don’t want one any more, just swipe that row to the left to delete.
  3. You must now explicitly ask for a new set of cards to pray for on any given day. If you like to pray for same things all day long, now you can! Once you’ve prayed, your cards will stay the same until the following day. If you prefer to pray for new things every time, there’s a button you can press to ask for a new set of cards.

The update also includes some other minor updates:

  • You can now create a bunch of subjects by entering a simple list of names
  • Subject ordering should now be respected properly in prayer mode
  • The date that you last contacted somebody is now tracked, so you know how long it’s been
  • New “Help” gallery, which will be gradually expanded over time

P.S. Bonus points if you spot the glaring typo in this update. I’ll try to fix it soon!

New PrayerMate for Android Features!

PrayerMate Logo 1Today I’m pleased to announce the release of the first big update to PrayerMate for Android. It has a bunch of the new features you asked for:

  • You can now attach photos of people to their cards, as a little prompt to help you pray!
  • You can now backup your prayer database to Dropbox, and import it back again. This should be completely compatible with the iOS version as well, allowing you to transfer your data between devices. (Note: if you have any trouble re-importing, do get in touch by hitting the ‘send feedback’ button inside the app)
  • Subjects can now be scheduled by date, by day of the week or by day of the month, in addition to the “default” scheduling mode.
  • I’ve added an explicit button to ask for a new set of cards on any given day, so you can choose whether to keep praying the same stuff or for new things each time.
  • It’s now possible to choose to install the app to an SD card rather than directly to your phone, if you’re running out of space.

There’s also plenty of bug fixes:

  • The reminder alarm is now properly fixed for all users – apologies for any inconvenience caused by this malfunctioning for some of you
  • The app now better tracks your state and how far you had got through praying
  • Some subjects that had got “stuck” should now be back in circulation
  • Fixed a few crashes whilst managing your data

Let me know how you get on – you can email me through the app, or follow @PrayerMateApp on Twitter, and PrayerMate is on Facebook too. Do leave a review on Google Play if you enjoy it!

How an ancient story from the Old Testament still affects software development today

Want to make a computer programmer groan? Just ask them to explain “unicode” to you and watch what happens, as all of the joy drains out of their face in an instant.

It turns out that an ancient story from one of the very earliest chapters of the Old Testament still casts a shadow over software development in the 21st Century. Which story? The account of the Tower of Babel and God’s subsequent judgement on the world – a judgement which still makes itself felt these many thousands of years later.

In the days of Noah, God recognised that the intentions of man’s heart was “only evil all the time”, and so he made a fresh start of the world, beginning again with just Noah and his family. Yet the human capacity for evil was undiminished, and it’s not long before we see the human race trying to exert their independence from God: “Come, let us build ourselves a city and a tower with its top in the heavens, and let us make a name for ourselves, lest we be dispersed over the face of the whole earth.”

In one of those verses that proves what a sense of humour God has, we read that whilst they were busy trying to build the tallest tower imaginable, reaching to the very heavens, God still found it necessary to “come down” to get a closer look at the city and the tower, which the children of man had built.

“And the Lord said, ‘Behold, they are one people, and they have all one language, and this is only the beginning of what they will do. And nothing that they propose to do will now be impossible for them.'”

It was a period of unprecedented harmony for the human race, but how did they choose to use that spirit of co-operation? To rebel against God and try to throw off his shackles, making a name for themselves. Even then, God loved us too much to leave us to this rebellion, and so he proposed a judgement fitting the crime:

“‘Come, let us go down and there confuse their language, so that they may not understand one another’s speech.’ So the Lord dispersed them from there over the face of all the earth, and they left off building the city. Therefore its name was called Babel, because there the Lord confused the language of all the earth.”

Whilst their great intention was to prevent themselves being dispersed across the face of the earth, God did the very thing that they were afraid of and caused them to divide and spread out across the earth. He muddled their languages so that the unity they had previously enjoyed was destroyed, and in its place there was misunderstanding and gobbledegook.

And that, my friends, is why software developers today still have problems making their programs handle foreign characters properly. It’s not simply that computers can’t agree on what language to speak – in many ways, English is the common tongue of most software. It’s that even when there IS agreement on the language, computers can’t even decide quite how to represent that language. As Joel on Software explains in his excellent little introduction to Unicode:

“In Unicode, a letter maps to something called a code point which is still just a theoretical concept. How that code point is represented in memory or on disk is a whole nuther story.”

The humble apostrophe causes no end of problems in even otherwise very straightforward English documents, if you use the curly kind rather than the straight line variety, since depending on the character encoding you use to save your document its codepoint could be presented in all manner of different ways: ISO-8859-1, UTF-8, UTF-16, big-endian, little-endian, blah blah blah. When you start getting in to languages with lots of accented characters like French, or even whole different alphabets such as Chinese, then it starts to get completely unmanageable unless you understand what you’re doing. And even when you understand what you’re doing, chances are you’re having to interact with libraries and services which DON’T understand what they’re doing, or which decide to handle things in an ever so slightly different manner.

So God’s curse on the sinful intentions of our hearts is still making itself felt even today. It can add all sorts of overhead when trying to get software based on different platforms to talk to each other. We’ve come a long long way from where we were a few years ago, but even so it can still cause much banging-ones-head-against-a-wall.

And so we cry, “Come, Lord Jesus!”

Letting people subscribe to your prayer diary by email

People have been asking for this for a while, so I’m pleased to announce that if you have set up a prayer diary on the site, then it is now possible to allow people to subscribe to your content by email if you sign up for a service such as MailChimp (which I love, by the way!)

1. Create a campaign

Step one is to log in to MailChimp and create yourself an “RSS-Driven Campaign”

RSS Driven Campaign

2. Enter feed URL

You’ll need to provide a feed URL:

RSS Campaign URL

You can get that URL by clicking the “Subscribe by email” link in the right sidebar on your prayer diary:

Subscribe by email sidebar

3. Configure email template

Next you’ll want to set up your email template. MailChimp allows you to use some special code in your template to embed the contents of the feed in your email – if you’re using a different email service then you’ll need to figure out what the relevant code is for that service (I’m afraid I can’t help you with this). Try copying and pasting this into your template:



4. Create a signup form

Then all there is to it is to publicise your mailing list and let people subscribe. MailChimp also provides tools to let you create a mini signup form:

Signup forms

When given the choice, choose “General forms”, and then you can easily set up a form to let people join your list.

5. Go!

Then just enable your campaign and watch it go!