Android Development - Selecting a phone.

 At some point during your during your first android development project you are going to have to break away from the emulator and do some real world testing of your new app. For this you are going to need at least one android phone.

The gaps between a real phone to test and the emulator are significant, and it will save much development time if hardware testing is done before release.

One of the main gaps is how your app will react to the user events via actual hardware. Screen events from the emulator are an approximation of what actually happens on the device at best, for example responding to a single tap on the screen corresponds to a single mouse click on the emulator, but you will find on an actual device multiple touch events are received even for a very  brief tap on the screen. Also the other hardware sensors like the accelerometer and compass are often quite difficult to emulate so going to the hardware can speed up development.

A large part of the decision process for selecting a phone will depend on the different phone models availability in your location and your budget, this guide will focus on general advice and resources rather than specific models.

Check the hardware. There is a significant segmentation in android hardware with screens ranging from 240x320 to 480x800 and processors from about 400MHz. to 1GHz. ram can be anywhere from 128MB to 576MB currently and this will have a big impact on the performance and upgradeability of the device, as there is talk of android 2.2 not being supported on devices with less than 256MB and there are also rumours that android 3.0 will need 512MB. The type of touch screen (resistive or capacitive) will impact how sensitive the screen is and its general useability. As a general guide go with the following :

Screen >=  320x480
Processor >= 528MHz.
Ram >= 256MB.

A capacitive screen is generally preferable to resistive also check whether the screen is capable of supporting multi touch. Check the model your after has the other sensors/connectivity (accelerometer,  gyroscope, compass, GPS.

If you go for a high end device (480x800, 1GHz, >512MB) you should be fairly confident it will be supported up until android 3.0 after that who knows though.

Check the Android version.  This is heavily dependent on the manufacturers, For some phone models the android version the phone was released with will be the only version it ever gets, other manufacturers are more proactive with supporting older devices (where a device is considered old after 6 months!). It is crucial to check how well supported the phone is by the manufacturer so you are not stuck with a legacy device. A lot of phones are still being sold with 1.5 (Feb 2009) and 1.6 (Sep. 2009) versions of android which are pretty long in the tooth when the current version 2.2 was released in May 2010. If you are building apps to support the maximum number of users an older android version does give you a lowest common denominator approach so designing and testing on a 1.5 device might give you access to a larger user base than designing for the latest and greatest version.

Check the forum support.  A popular phone with very active forums will be a lot easier to get along with than one that is unique to yourself, as you will have to solve every problem on your own. Phones with very active forums will often be easier to root which gives you access to wider variety of software and they will also often have custom roms available which will may allow you to upgrade a 1.5 device to 2.1 (for example) even though the manufacturer has not released any updates.

Here are a couple of good starting points:

xda-developers
modaco

Also as a rule of thumb the googles current phone model (Nexus One) gets the latest versions of android well ahead of other manufacturers and offers few barriers to providing an excellent development experience.