Sorry, Actually I didn't receive an email notification for this comment that's why I am late to reply.
Yes, this project is still supported.
1: It accepts jpg, jpeg & png image formats
2: Yes, Any other programmer can easily edit the code if they knows PHP - PDO
3: Thanks for reporting this, I will look into it .
Bonus : You can easily grab the offer for my bundle i.e. CodeDaddy Mega PHP Bundle Mega Loot Offer in which my all items are included and my future item will also be included. Currently, it has 48 PHP Scripts and in Future it will be 100+ PHP Script Bundle.
Here's the link
Thanks & Best Regards