This is an impressive app. It’s not free, but very cheap, and available for iOS and Android.
While it would not usually be thought of as an art activity, it is by definition visual culture. It’s also fascinating, and a little step towards greater social inclusivity.
(It’s odd to think that there is an easily accessible, whole extra modality of communication that society could be using … but doesn’t.)
(If you’re wondering about sign language and Northern Ireland, you may be thinking “I bet there’s two different sign languages there…” Nope! … there may be three – Wikipedia. Apart from ISL there is definitely British Sign Language (BSL) in NI; if anyone can recommend the best site or app for BSL, it will be included in these Isolation Activities.)