I've created a cross-platform mobile app called "Tonestack Kit" that builds on Dave Cigna and Duncan Munro's work in Duncan's Tonestack Calculator. The iOS version is available now in the App Store. I am in the process of testing the Android version and should have that available in the next few days.
Out of the box, the app includes the 7 of the 8 tonestacks in Duncan's TSC (plus Merlin's "Bone Ray" tonestack). There is an in-app purchase ($3.99) that adds an additional 12 tonestacks. Apple is a bit picky about the use of trademarked names, so there are some minor changes to the naming of the tonestacks. Here's the full list of available stacks, along with the full model and/or name in Duncan's TSC:
Free:
AB763 (Duncan's "Fender" circuit)
Plexi (Duncan's "Marshall" circuit)
DR103 (Duncan's "Hiwatt" circuit)
E-Series (Same as in TSC)
James (Same as in TSC)
Top Boost (Duncan's "Vox" circuit)
Tilt (Same as in TSC)
Bone Ray (Developed by Merlin Blencowe, "The Valve Wizard")
Full version adds:
60TC (Carlsbro 60TC)
6G7 (Fender Bandmaster)
Baxandall
Guitar Mate (Traynor Guitar Mate)
Voigt
18W Normal (Marshall 18W normal channel)
18W Tremolo (Marshall 18W tremolo channel)
5F2A (Fender Princeton)
6162 (Gretsch 6162 Twin Reverb)
Bridged-T (Bridged-T mid control, Gibson-style)
Bridged-T Alt (Bridged-T mid control, Framus-style)
Moonlight
The app has basically the same features as Duncan's TSC: you can fully edit the component values on a schematic-like layout, move sliders to simulate tone and/or volume knobs, load/save circuits, and export the chart and schematic as images or .csv files. Additionally, you can pan and zoom the chart and highlight guitar/bass frequencies on the chart.
After finishing the Android version, I'm going to take a short break, but eventually I would like to add a little more user control to the appearance of the chart (background color, line thickness, frequency range) as well as a darker "theme" to the app. I'd also like to investigate modelling some "active" tone controls, or ones with interactive channels.
Anyway, please try it out and feel free to ask any questions or for other features and/or tonestacks you'd like to see. I put a lot of work into developing a set of general algorithms I can use to model a given tonestack and handle the editable schematic, and it only takes me a couple of hours to add a new tonestack. If there's a particular one you'd like to see modelled, I'd be happy to add it to a future update.
I'd also like to thank Duncan for his assistance. I started this project a couple of years ago, and Duncan was kind enough to point me in the right direction back then when I was just getting started.
I'll add a couple in the next version.