I use Krita, Ibispaint, and Photopea, but the program you use wouldn't matter. Just as long as you can make a small cavas and can import images, you can make these!
Ezgif is a very important resource to have in this!
Blinkies are very simple to make! They're typically only 2 frames long.
Blinkies need to be 150 x 20 pixels big or an equavilent size!
You can make your own stamp template or use one from somwhere else. I use this template:
Import the stamp template in your program, and import your image into it.
If you want it to be a gif
This way is slightly more complex, but also luckily only uses Ezgif!
Grab your gif you want to use, or make one in video to gif.
If the gif isn't in a landscape size, crop it to be that way.
Go to resize, make the dimensions the size of your stamp template MINUS the size of the borders. For example, the thickness of the border on the 99 x 56 stamp template i use is 3 pixels wide for each stampy bit, so take 6 (3 for each side of it) away from 99 and 56, so you get 93 x 50! Make sure to make it “stretch to fit” as well!! Also, as a tip, keep this tab open just in case you miscalculate the size of your gif!
Go to “add overlay”, go on the “extend canvas size” button, then import your stamp template. Then you just move it to fit over your gif. If the resizing goes well, it shouldnt have any transparent lines in the border!
Extending the canvas size will result in a lot of transparent pixels around the image, so go to the “crop” button, and check the “autocrop” thingie, and then your stamp would be the correct size!
This is optional, but i heavily suggest you optimize your stamp as well! You can totally just download it as is, but: