I downloaded an Android keyboard app with arrow keys and was able to play TagPro (albeit very badly) on my phone : r/TagPro
Free Keyboard with Arrow Keys for Android
How to use your mobile keyboard as a text cursor while typing
The Keyboard - The Sprint HTC EVO 4G Review
Amazon.com: Gishine WiredWireless Mechanical Keyboard 63 Keys, Bluetooth Mini Keyboard GamingOffice for iOS Android Windows and Mac with Red Switch -White&Pink : Electronics