My primary recommendation is Zerodha Coin, and secondary recommendation is ET Money.
Zerodha Coin is very specific to mutual funds, but you can also buy bonds (limited), Government Securities (GSecs), Bills etc. In addition to standard features like SIP etc, you can create conditional buy orders for mutual fund. For example buy XYZ mutual fund when its NAV falls below a certain price. The mutual funds units are directly deposited to your Demat account (CDSL). However, you need to have a Zerodha trading account. Payment is deducted from your linked Zerodha trading account, or you can setup an e-mandate from your bank account.
ET Money from Economic Times group is a good fully featured app to buy mutual funds, FDs, liquid funds etc.
With ET Money, the purchased mutual funds units are held by the fund house, unlike Zerodha where the mutual fund units are credited to your demat account.
