Banner Creator Recommendation ???? Can we use Banners our Ads?

I am requesting a free, Banner program, website that you have used & would recommend.
The simple animation program I used today was very limited basic & didn't have image upload capabilities, :damncomputer:
Tablet friendly a must without having to download a large file would make me scream for Joy.
Has anyone used online, animated Banner creators?
I know we can place banners in our signature lines but can you use a different Banner in our designated advertisement for companions?