Updated: May 16, 2019
My children are totally obsessed with these melting beads activity kits right now.
The kits come with a design board and lots of patterns, so my 6yo spends hours sticking the miniscule beads into miniscule holes. We're currently in a mass production phase of unicorns, cats, hearts, cupcakes and lollipops.
Once the design is finished you iron it and the beads melt and they become a toy (or a jewel, or a masterpiece, you decide).
It's definitely only recommended for 5+ as it's quite a tricky activity that requires lots of patience.
Although that's not a problem for my 3yo who has commissioned me to create all her designs while I stop the baby from choking on the miniscule beads. Fun!