Life & fun · alternatives · 2026

24 alternatives to Theorem

Pay What You Want

Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Theorem launched in 2014; newer entries below may have overtaken it.

1. 1
   Paid▲124

   An API for invoicing

   2015 · paidapi.com · its alternatives →

2. 2
   Plasso▲139

   Payments Made Simple

   2014 · its alternatives →

3. 3
   Paylike▲86

   A modern full-stack payment platform

   2015 · lunar.app · its alternatives →

4. 4
   Comparably▲194

   See what people like you get paid

   2016 · comparably.com · its alternatives →

5. 5
   Space Box▲100

   Payments made simple

   2014 · its alternatives →

6. 6
   Mango▲69

   Better payments

   2014 · mercadolibre.com · its alternatives →

7. 7
   Ship It ▲109

   Turn your product idea into a paid prototype

   2016 · femgineer.com · its alternatives →

8. 8
   BarterPlace▲75

   A Marketplace to Trade Skills

   2014 · its alternatives →

9. 9
   Tink▲71

   Follow your money.

   2014 · macpamalaysia.org · its alternatives →

10. 10
    Funded.io▲86

    easy financial modeling

    2014 · funded.io · its alternatives →

11. 11
    Pay with a Tweet▲193

    Sell your product for the price of a tweet

    2014 · paywithatweet.com · its alternatives →

12. 12
    Denominations▲55

    Think in another currency

    2014 · denominations.app · its alternatives →

13. 13
    Dollars for Docs▲90

    How industry dollars reach your doctors

    2015 · its alternatives →

14. 14
    Question Down▲61

    What Would You Pay $1 To Know?

    2013 · its alternatives →

15. 15
    Trekonomics ▲76

    The economics of Star Trek

    2015 · inkshares.com · its alternatives →

16. 16
    Fluky▲105

    A friendly randomiser

    2014 · fluky.io · its alternatives →

17. 17
    Txt2Give▲70

    Make giving easy and raise more money

    2015 · txt2give.co · its alternatives →

18. 18
    Probs▲78

    Free crowd-sourced problem solving

    2015 · its alternatives →

19. 19
    Checkparty▲64

    Split the bill with friends

    2015 · checkpartyapp.com · its alternatives →

20. 20
    Freemium Economics▲89

    A nuts and bolts guide to Freemium

    2014 · amazon.com · its alternatives →

21. 21
    Popular Pays▲63

    Now accepting social currency

    2014 · its alternatives →

22. 22
    Mathway▲78

    Math Problem Solver

    2014 · mathway.com · its alternatives →

23. 23
    Vouch▲90

    Friend powered finance

    2014 · vouchmoney.com · its alternatives →

24. 24
    Square Order▲95

    Order from your phone

    2014 · squareup.com · its alternatives →

Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →