There are many apps that help you make a few quick bucks. But please note that these apps provide quite a little amount for all the effort you are going through. A few such are -
1. Dreamstime
If you have good photography skills, you can register for an account with Dreamstime stock photography site and use their Dreamstime Companion app to upload images you have shot. You can offer your masterpieces either as commercial or editorial purposes. Once your images are sold, your earnings will be added to your account.
2. Screenwise Panel
Thus is one of the Google initiatives. You need to register yourself on the screen wise panel with your Google account and install Screenwise Panel app from Play Store. That's it - you do not need do anything else. You will earn Rs. 300 as joining bonus. Rs. 100 per month will be added to your earnings just for keeping the app installed. If you are concerned about your privacy, you may decide against it. Though Google has made clear that it will not access any private information, there are no words as to what exactly Google has access to.
3. AppNana
The app let a you download apps and you get points in your account. It works on sponsorship.basis for app downloads. However, you won't earn much from such apps.
There are many apps that promise better revenue on app downloads. But, most of them do not appear reliable enough. You can, however, try the ones like CashPirate, AppRedeem and MCent.
MCENT had been a great app to earn mobile recharge. It used to offer Rs. 5 as a minimum for a single app download. But these days have been unreliable as I could not redeem a few mission completions. I have deleted the app since then.
Screenwise Panel has been promptly letting you get the rewards to your account. You can redeem the amount for gift cards from select e-commerce stores like Flipkart and Myntra.
Live....and Let Live!