I am using imo messenger from past 6 months it provides good video calling at a normal speed I didn’t experience it but after experiencing it I myself got shocked when I had 2g in my cellular data I could do video call there was some lag but though lagging it provided a good response I loved it especially the stickers in imo messenger very unique and cute it has more than 1000 stickers which is very useful but not handy must search for required sticker apart from this imo is wonderful messenger