flow can be used in Android under termux, inside termux, follow installation instructions,i.e., just copy paste and you are up and running.
Recommended to install monospaced fonts and icons to have the most comfortable experience.
Termux-nf offers various fonts to choose from, install the fonts installer and the choose your desired font, for example the same fonts of this website:
curl -fsSL https://raw.githubusercontent.com/arnavgr/termux-nf/main/install.sh | bash
getnf -i NerdFontsSymbolsOnly
getnf -i Iosevka
If you run into issues with font installation, install termux-nf required packages pkg install curl ncurses-utils or consult their website.