SplitsTree, PhyloSketch, CatReNet and PhyloParallelograms as native iOS apps
SplitsTree App computes and visualizes phylogenetic trees and networks. It reads distances, aligned DNA, RNA or protein sequences, trees and splits in Nexus, FASTA, Newick, PHYLIP and other common formats, and offers the methods of the SplitsTree desktop program: distance methods such as neighbor-joining, neighbor-net and split decomposition, consensus trees and networks, the phylogenetic outline, rooted networks, and interactive tree, network and tanglegram viewers. Analyses are set up in the same workflow as on the desktop, and documents can be exchanged with the desktop program without conversion.
The app is designed for the iPad and also runs on the iPhone.
Paper: Daniel H. Huson and David Bryant. The SplitsTree App: interactive analysis and visualization using phylogenetic trees and networks. Nature Methods (2024). doi:10.1038/s41592-024-02406-3
Desktop program: github.com/husonlab/splitstree6 (GPL 3).
App Store: SplitsTree App is available on the App Store at apps.apple.com/app/id6476155107, or scan the code below with your iPhone or iPad.

Beta testing: new versions are tested through TestFlight before they are released; to try them, join at testflight.apple.com/join/MGiPWSuc.
Documents are kept in the app’s own folder on the device. The files tab of the app lists them, and the same folder is visible in the Files app under On My iPhone (or On My iPad), where files can be copied, renamed or moved to iCloud Drive. To bring a file into the app, share it from another app, from Mail or from Files and choose the app, or copy its text and use Import > Paste into new file in the files tab. To get data out, use Export in the files tab or the export items in the document itself: they open the system share sheet, from which files and images can be saved, sent or copied.
Questions and bug reports: see the support page. Privacy: the app does not collect any data, see the privacy policy. The third-party software included in the app and its licenses are listed on the licenses page and in the app’s About pane in the files tab.