Simple Poulty app uses open source icons available freely on internet. Below are their attributions.
"Icon made by Freepik from www.flaticon.com"
“Icon made by Smashicons from www.flaticon.com"
“Icon made by cuputo from www.flaticon.com"
“Icon made by Mayor Icons from www.flaticon.com"
“Icon made by amonrat rungreangfangsai from www.flaticon.com"