Upcart—Cart Drawer Cart Upsell

Pros-
1.)Easy to use and configure
2.) Available everything in hand like 3 steps progress bar
3.) Easily integrates with the theme

CONS-
CHARGES ARE WAY TOO HIGHER
DOING 1000 ORDERS AND USED UPSELL IN 60 ORDERS
CHARGED ALMOST Rs.8000 including subscription fees and it shocked me when i saw the usage charges at the end of month (my bad)

Neutral, one can find a few more apps cheaper than this as one may need to configure other with a much more hassle but it is only a 1 time job to configure it.