Constructive Calculator

Reviewed matches are labeled. Other suggestions come from a shared subcategory, use case, source listing or the same category. Compare features and current plans before choosing.

Product
Solve (Clever Calculator) Scientific calculator for students and engineers
WristConvert Unit converter for Wear OS watches
The Time Resource World clocks, time zones, and timing tools
Easy App Library Free online games tools and calculators
excelmacros.net Describe your Excel problem. Get the right macro in seconds.
Timerjoy Free online timers, countdowns & date calculators
SudoTool Free online tools and calculators, no signup, no uploads
Cifrivo Online tools for PDF image and unit conversions

Selected by category and available use-case details. A topic match does not establish equivalent features.

Product
Memura Second brain for busy minds. Brain dump it, ask it back.
Sun Track Habits, Manage Todos
WakeMinder Reminders that pop up the moment your Mac wakes.
Convertica Free online tools to convert, edit, and organize PDFs
Mindlo Turn scattered notes into clear next actions
ReminderCalendar Share reminders and manage team calendars

Added to this directory in the past 30 days. Dates refer to the directory listing, not the product launch.

Product
Pavleur AI copilot for live transcription and recaps
SubPure: Subscription Tracker Track your recurring expenses and avoid surprise charges
VoiceLetter: to Future Self Send voice time-capsule messages to your future self
ClipKeeper: My Clipboard Vault Save and manage important clipboard text manually

Profiles grouped by topic. This does not confirm an offer, availability or a connection to this profile.

Profile
David Allen American productivity consultant and author
Technomanagers IIM Bangalore & IIT Kanpur alumni are helping you land your dream career in Management or Technology.
B Ben Doolan Founder/COO at TamLabs

Shows and channels grouped by topic. A recommendation does not mean this profile was featured or endorsed.

Show
Thoughts from the Ivory Basement Newsletter · Günter Richter
Top SaaS & AI Tools YouTube · 130K subscribers
Ai & SaaS Lab YouTube · 10K subscribers

Retold founder accounts from startups in the same category, each linked to the original.

Story
Buffer's first paying customer arrived four days after a seven-week build Joel Gascoigne validated Buffer with a two-page landing flow, spent seven weeks of evenings and weekends on a minimal product, launched on 30 November 2010, and recorded a first paying customer within four days.
Tibo stated sub-$2M ARR at sale and $6–7M later, not catalog $3.5M In a January 2024 Bootstrapped Founder interview, Thibault Louis-Lucas did not quote a $10M sale price or $3.5M ARR; he said Lempire acquired them below $2M annual recurring revenue and that they were nearing $6–7M, with
Tally's March 2024 letter is $100k MRR, not a $3M ARR stamp Marie Martens wrote that Tally, launched in summer 2020 with Filip, hit $100k monthly recurring revenue in February 2024 with a bootstrapped team of three and more than 250,000 users; this record uses those founder label
Ajay Goel priced GMass after a free year, not after an ARR headline Ajay Goel’s own GMass posts give send volume, user counts, and plan prices. In a later interview he described a $10,000 first build, a free first year, and $10,000 to $20,000 a month after the paywall. He did not state $

Subcategories in the same part of the directory, with the number of listed products.