If you want to cover a wide spectrum of the market and use OpenGL ES you have to chose by GPU. You should
have at least one device with:
- A Qualcomm chip (preferably an Adreno 200 or above). Anything from HTC will do that's more recent than 8 months.
- A PowerVR chip. Samsung uses PowerVR in many of it's mid to top range of phones. Some Motorola phones feature a PowerVR as well.
- A Tegra 2 chip, see basically every new phone and tablet