Just had an awful experience with WPMU DEV, I bought a plugin from them and it was so rotten it actually took my website offline for a few days. Their support was absolutely useless too. Googling around, it would turn out I should have known better than to go with them. A lot of their positive reviews on closer inspection look fake and there are many reports of them actually stealing money (including a chldren’s hospital!) so I have logged into my bank account online to block them before they try to rob me too now.
So with WPMU DEV being awful and thieving, can somebody reccomend a good plugin store?