I would recommend the following
Ebook readers for a better experience -
1. Kindle -
Being the trendsetter in Ebook reader space, Kindle is the top name among the contemporary readers. Having a clutter free interface and great usability, the app has best collection of ebooks. Downside, however, is you cant get many free ebooks on it.
2. Flipkart EbooksThis is my all time favourite. It has a good collection of Indian authors. You can also get good ebooks for free, or for a nominal price. Major plus point of the app is, in addition to being a premium reader for Indian users - it can also be used as a default Ebook reader for your personal downloaded collection.
3. AldikoOne of the popular Ebook readers, it has support for multiple formats. Just like Flipkart Ebooks, it can be used as a default reader for your device.
4. KoboThis one has an extensive library. It is unique in itself as it gamifies the reading experience. But, the books available on it are quite expensive.
5. RockstandThis is the most basic Ebook reader available. Book library is a bit limited. It has a good Indian collection. Pricing of the books is quite low.