Honestly, Ive tried a bunch of these for our family reunions and unfortunately, most of them have become pretty bloated with unnecessary ads and tracking. It is really annoying when you just want a simple list. I used Elfster for a few years, but I had issues with the interface being way too cluttered for my older relatives to navigate. My grandpa basically gave up because there were too many popups and suggested gifts everywhere. It was not as good as I expected it to be for a free service. If you want something that actually works without the headache, here are a few things to consider:

• Giftster is usually my go-to now. It feels like a private registry and not a marketing tool. You can make a private group so only family sees it, which is better for privacy.
• Amazon lists are okay but honestly a letdown. They force everyone into their store and the sharing settings are a nightmare for people like your grandpa who arent tech-savvy.
• Google Sheets works if you want zero fluff but it lacks the Secret Santa shuffle thing. Whatever you pick, make sure it doesnt require a paid subscription. Most of the premium wishlist apps are just charging for features that should be free, which is pretty disappointing. Stick to the ones that let you add items from any store via a link copy-paste. It really shouldnt be this hard to just share a gift idea without being sold something every five seconds... especially for a trip to Chicago where you should be focusing on the fun stuff.

TL;DR: Use browser links so older family members dont have to download anything. Be careful with apps that require everyone to create a password; it always causes drama. I would suggest Share Product Wishlist as a simpler alternative. I used it for our last big trip and it was a total lifesaver for the non-techy folks. Just make sure to check the privacy toggles before you share it!