This is a quick overview of the pros and cons of iOS & Android apps.
From a marketing point of view you need to release on both platforms, unless you have very strong technical reasons not to.
The discussion below is really about which to develop first. I'm aware that quite often projects need to do synchronise releases in which case this doesn't really apply :-)
Android - Pros
- Quicker to release/patch because there is no 'acceptance' gate forced on you - ideal for a part-formed product, i.e. the Minimum Viable Product or MVP
- Wider install base - you have a broader population of people with Androids (especially outside the US)
- Easy to develop using existing PCs and Eclipse, i.e. not specialised hardware
- No restrictions on what you develop, so its open to new ideas
- Two key markets to submit to: Google and Amazon, which means you can have multiple shots at success
- No restrictions on deploying beta/alpha versions
Android - Cons
- Fragmented devices - lots to support (screen sizes, performance, sensors)
- Fragmented OS - lots of users will be on a range of OS versions (you can choose to not support older OS/Devices). See note below
- Two key markets to submit to: Google and Amazon - potentially means more fragmentation to support any custom API's
- No double checking of the final app - therefore all the QA is with you (it is with Apple too, but they might just spot a real showstopper)
- Emulator isn't a good as iOS (not a big issue as getting the app on the device is trival), and generally Android devices are cheaper than iOS
iOS - Pros
- iOS products are premium therefore potentially a more lucrative set of people to sell to
- Easier to develop - only a small set of hardware/OS to support
- Easier to develop with regards UI standardisation
- Standard tool chain so most problems have been solved before
- Quality is higher than Android, so its harder to publish a bad app. (This is a pro and a con.)
iOS - Cons
- Requires approval by Apple for every app released (this can delay vital fixes for several days, for example).
- If Apple don't like the app that you lovingly crafted over the past 6 months, that's it - no income.
- Quality is higher than Android - beta apps will be rejected, so you have to have a fully functional app
- Very difficult to get noticed in the crowd, especially with the app stoire design of only showing a small number of search results (one per screen in the case of iPhone)
- When searching for apps the reviews shown are only for the current version (the review count is reset on every update you issue, and in turn that affects sales)
There was a period when targeting just iOS or Android was an option, but I think now there is no choice - you have to tackle both. I would probably recommend doing the Android dev first to "iron out" all the app to behave as required, mainly as Android allows you to update frequently without a review / delay penalty. Then when you have the product features ironed out, port to iOS, but don't wait too long if its a unique and compelling idea.
NOTE: Users on old devices/OS's - in our experience the lifecycle of owning a phone/table hasn't changed much since the Symbian/J2ME days.
- Owners of new devices download lots of content/apps and generate the core revenue (in their first 3-6 months of ownership)
- After a while they settle into a routine and don't download much at all (6+ months)
- Eventually their purchases drop away, until they update their device (12-18 months), and the cycle starts again
This is important when you're deciding which OS/devices to support, and you find that say the bottom 50% of users consume 80% of the resource to support, but don't represent the bulk of the revenue. Back when Teazel created J2ME games it wasn't uncommon to have 27 separate builds per game. In those days you would get a list of devices to support from the operator, along with the percentage of sales that came from each device. You could hit 60/70% by supporting the later Nokias and Samsungs, but chasing the rest required more and more builds.
Our current advice is to target Android 4+ upwards, and iOS 6+.