Honestly, skip the apps. They always seem to glitch with international stuff. I've done this for years with groups like yours, and the best way is just to manually assign people within the same country. Use something like the Christmas lists chrome extension to keep track of everyone's items in one place. It saves you from dealing with insane customs fees and makes the whole process way less stressful for everyone involved.

Honestly, I used to stress about this exact thing every single year until my group finally just kept it simple. I have used a basic online organizer for years that lets you group people by location, which honestly saved my sanity. Setting it up so everyone only draws names from their own region keeps the shipping costs super manageable and honestly stops those annoying customs headaches too. For the lists themselves, I really love using Share Product Wishlist because it makes everything so easy to track without needing a messy spreadsheet. It works well and I have had no complaints from my friends so far. If you are all really tight on cash, just stick to digital gift cards for the folks who are too far away, honestly. It is just so much easier than paying a fortune at the post office.