Azhagi+ (AzhagiPlus) is described as 'It is a software which allows users to type in many Indian languages like Tamil, Hindi, Sanskrit, Telugu and more. It also supports a phonetic keyboard for these languages' and is an app in the OS & Utilities category. There are three alternatives to Azhagi+ (AzhagiPlus) for a variety of platforms, including Android, iPad, iPhone, Windows and Mac. The best alternative is Keyman, which is free. Other great apps like Azhagi+ (AzhagiPlus) are Sellinam (Free) and PolyglotKeyboard (Free).
With keyboards for over 1000 languages, Keyman Desktop lets you type in your language even when Windows doesn't. You can even create your own custom keyboards with Keyman Developer 9.0. The free version offers 2 languages.
PolyglotKeyboard is an application for polyglots, for people, who need to type different languages (nearly) simultaneously. It allows using simple keyboard shortcuts for writing desired special characters found in different alphabets.