
PEAR
Hecto
Letterfuel
Duuce
Swapstack
BuySellAds
AdSense
Buy and sell ad space in email newsletters

NovoPsych
Clinical assessment tools for psychologists, therapists and occupational therapists. Send measures by secure link and review scored results, severity bands and reports.

Which is more popular?
Based on our record, LetterWell seems to be more popular. It has been mentioned 7 times since March 2021.
Website, pricing, platforms and company facts side by side.
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| Website | letterwell.co | clientforms.app |
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In their own words, as submitted to SaaSHub.


Letterwell is a platform to buy and sell advertising space in newsletter emails. We provide a secure, thoroughly vetted marketplace to connect advertisers with newsletter owners.
Clinical assessment tools for psychologists, therapists and occupational therapists. Send measures such as the PHQ-9, GAD-7 and DASS-21 by secure link and get scored results, severity bands and reports ready to review. The catalogue also includes DSM-5 ADHD assessments and autism screening tools....
What each product offers, as listed by its team.


An editorial look at what each product does well and who it suits.


No analysis of LetterWell yet.
Overall verdict
Why this product is good
Recommended for
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing LetterWell and ClientForms.app.
ClientForms.app's answer:
Frontend: Next.js 15 (React 19), Tailwind CSS Backend: Supabase (PostgreSQL, Row-Level Security) Authentication: Clerk Payments: Stripe Hosting: Vercel (Sydney region) Database hosting: Supabase (Australian data residency)
ClientForms.app's answer:
Psychologists who assess ADHD and autism. Typically private practice, solo or small group (1-5 clinicians), currently using paper forms and spending hours on admin per assessment. They want something that works and is secure.
ClientForms.app's answer:
Neurodivergent-first design. Most digital forms just replicate paper online. ClientForms is built specifically for ADHD and autism patients - progress bars with time remaining (helps with time blindness), softer colours instead of harsh white, sticky headers so you always know where you are. The forms are designed to reduce anxiety and improve completion rates.
ClientForms.app's answer:
Most clinical software treats patients as an afterthought. ClientForms is designed specifically for neurodivergent users who are filling out the forms, progress indicators, time estimates, calmer colours, predictable layouts. One link, no signup required, works on any device. Patients just open and complete.
Share your experience with using LetterWell and ClientForms.app. For example, how are they different and which one is better?
Recommendations tracked on public social media and blogs since March 2021.


Do you guys have any feedback about https://letterwell.co allowing to find sponsors? I would be interested to know if it's effectively used by some newsletter creators. Source: almost 5 years ago
I haven't found one for larger newsletters, would be a great resource.. I know of some sites that allow newsletter owners to sign-up to find advertisers/sponsors: https://store.tryletterhead.com/ and https://letterwell.co/. Source: over 5 years ago
Hey, I'm looking for newsletters where I can advertise my website and I wanted to ask if you know cool publishers who offer this in their newsletters? (something different from letterwell.co) Thanks in advance! Source: over 5 years ago
Tracking ClientForms.app since Dec 2025.
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Grow your audience with a curated newsletter
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First marketplace for buying and selling Newsletters.
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Swapstack, now acquired by beehiiv! Check out what we're doing over at beehiiv's incredible ad network: https://www.beehiiv.com/features/ad-network/brands and come thrive with the hiiv!
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