How to start a Flexible Block Planner Instead of Time Blocking business: plan and growth
Classic time-blocking doesn't fit people who naturally group tasks into flexible blocks ('work 4 hours, clean, portfolio') rather than planning by the hour.
An owner can start “Flexible Block Planner Instead of Time Blocking” from a complaint people already posted. The offer, in one line: Plan your day as reorderable blocks of work with no fixed start times, halfway between a to-do list and a calendar. It is for knowledge workers and people with ADHD. Charge a free tier and a paid upgrade, and test a price under $10 a month. Begin in more than one country. Buyers already talk about this in r/productivity. One thread gathered 29 votes and 32 replies across Sep 14, 2026 – Oct 14, 2026. Use that room to meet the first twenty buyers. Do not export it, and do not republish the posts. The idea, the evidence, and the market estimate on this page are free to read. Two paid prompts finish the job: one drafts the offer, the price, and a ninety-day calendar; the other drafts a month of conversations and proof. One credit unlocks both. A software specification is not on this site. When the company is the product itself, a single link further down opens the founder library.
Does anyone else group tasks into flexible blocks…r/productivity · Sep 14, 2026 – Oct 14, 2026 · 29 votes · 32 replies · Open the thread
Who would pay
Knowledge workers and people with ADHD. Start in more than one country, and charge a free tier and a paid upgrade, testing a price under $10 a month.
The thread above is the public complaint this business can learn from. Verbatim quotes are not invented. Further sources, when a later report adds them, stay with the evidence.
What buyers use today
- Sunsama
- Akiflow
- Todoist
The offer, in our words
A planner built around flexible, reorderable activity blocks without fixed start times: a middle format between a to-do list and a calendar.
Score 2.40, Cool. Pain, willingness to pay, demand, and the gap in current options drive it. We are not scoring how fast you can code.
Market size
An estimate, built from the bottom up: real customer counts × a realistic price. It shows the size of the prize, not a forecast.
TAM Total addressable
$221M a year
4.6M adults · 30% of US adults with a current ADHD diagnosis
SAM Serviceable
$67.2M a year
1.4M adults · app-store and community reach
SOM Obtainable in 3 years
$672K a year
14,000 adults · 1% of the reachable segment in three years
What that means
14,000 adults at $4/mo = $672K ARR
Medium confidence · estimated Oct 2026
How we estimated this
- Base: 15,500,000 US adults with a current ADHD diagnosis.
- Has the problem: 30% (assume 30% have abandoned time blocking).
- Revenue per adult: $48 per year ($4/mo).
- Reachable: 30% (app-store and community reach).
- Three-year capture: 1% of the reachable segment.
TAM is customers with the problem × revenue per customer. SAM is the part a new business can reach. SOM is a cautious three-year share of SAM. The bars use a log scale. A share marked “assume” is our judgment, not a measurement.
The business-plan prompt
The offer, the price, and a ninety-day calendar, written for an agent. 1 credit unlocks both prompts for this idea: this plan and the growth playbook below.
# Business plan prompt: Flexible Block Planner Instead of Time Blocking You are writing a practical plan for one owner who will sell this as a business. Do not write a software specification, a venture memo, or a feature list. Use short sentences. Where a number is unknown, give a range and say what to measure. ## The business Working name: Flexible Block Planner Instead of Time Blocking What the customer gets: Plan your day as reorderable blocks of work with no fixed start times, halfway between a to-do list and a calendar. Who pays: Knowledge workers and people with ADHD
Locked · the first lines are above
Unlock both prompts for this idea · 1 credit ($9.99)
One credit opens the business plan and the growth playbook together, for good. Credits work on both businessideastobuild.com and realstartupideas.com.
Sign in once with your Real Startup Ideas account; the same credits work on both sites.
The growth playbook
Thirty weekdays of conversations and proof. Not an ad plan. Included with the plan above, on the same credit.
# Growth prompt: Flexible Block Planner Instead of Time Blocking
You are planning thirty days of distribution for a business that already has an offer. The offer: Plan your day as reorderable blocks of work with no fixed start times, halfway between a to-do list and a calendar. The buyer: knowledge workers and people with ADHD. Price band: under $10 a month.
Do not propose ads, a viral loop, or a rebrand. Propose conversations, proof, and a repeatable weekly rhythm.
## Starting point
A public thread in r/productivity drew 29 votes and 32 replies. The pain, in the owner's words: Classic time-blocking doesn't fit people who naturally group tasks into flexible blocks ('work 4 hours, clean, portfolio') rather than planning by the hour. Locked · the first lines are above
Unlock both prompts for this idea · 1 credit ($9.99)
One credit opens the business plan and the growth playbook together, for good. Credits work on both businessideastobuild.com and realstartupideas.com.
Sign in once with your Real Startup Ideas account; the same credits work on both sites.
Questions
How much money do I need to start?
Enough to talk to buyers and deliver the offer once. A service version can start with a written process and a way to take payment. A software version is a larger bet and is not required to test the price. The band to test is Under $10 a month.
How should I price it?
Test a price under $10 a month, charged as a free tier and a paid upgrade. Raise it after three paid pilots, not before the first conversation.
Where do the first customers come from?
r/productivity is the clue. A related thread gathered 29 votes and 32 replies. Show up there, follow the room's rules, and ask for conversations. Do not scrape it.
Do I need to write code?
No. The prompts on this page draft a plan and a month of growth. Code is a later choice. The founder site linked once below is where the build document lives, if you want it.
When the business is the software itself, the specification lives on the founder site. Read the agent PRD
A two-week build starts at $10,000 on that site, after a $1,000 scoping fee.
Plans and growth playbooks
One credit opens both prompts for this business.
The idea, the evidence, and the market estimate stay free. The business plan and the thirty-day growth playbook for Flexible Block Planner Instead of Time Blocking cost one credit, together, and stay unlocked.
Credits work on both businessideastobuild.com and realstartupideas.com. Sign in once with your Real Startup Ideas account; it is the same wallet.