
Google Voice
TextNow
RingCentral
ChucK
Burner
MightyCall
Hushed App
Sideline™ is the free 2nd number for your smartphone. It uses your existing carrier network so your 2nd number works anywhere your cell phone does.

Substack
Formo.so
Advanced analytics for Substack writers. Runs 100% locally, no cloud, no subscription. Discover your superfans, churn risk, and cohort retention.

Which is more popular?
Based on our record, StackStats.app seems to be more popular. It has been mentioned 1 time since March 2021.
Website, pricing, platforms and company facts side by side.
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| Website | sideline.com | stackstats.app |
| Pricing | ||
| Company | — | Startup from the United Arab Emirates · 1 - 9 employees · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of Sideline yet.
StackStats is a local desktop app for serious Substack writers. Import your CSV exports and get analytics Substack doesn't show you: bot-filtered open rates, cohort retention, dead subscriber detection, superfan ID, content-to-growth correlation, and an optional AI layer (supports Ollama,...
What each product offers, as listed by its team.


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


Overall verdict
Why this product is good
Recommended for
Overall verdict
Why this product is good
Recommended for
Walkthroughs and reviews on video.
Sideline App Review for iPhone and Android 2020
More videos
No StackStats.app videos yet. You could help us improve this page by suggesting one.
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing Sideline and StackStats.app.
StackStats.app's answer:
I built StackStats because Substack's native analytics weren't cutting it. I wanted cohort data, real open rates (not bot-inflated), and a way to identify which posts were actually driving subscriber growth — but every tool I found was either cloud-based or required migrating off Substack entirely. So I built a local app that works with Substack's own CSV exports. No migration, no cloud, no subscription.
StackStats.app's answer:
StackStats runs 100% locally on your machine — your subscriber data never touches a server. It also goes far beyond what Substack shows natively: bot-filtered open rates, cohort retention, superfan identification, dead subscriber detection, and content-to-growth correlation. No subscription, no account, no cloud. Pay once, own it forever.
StackStats.app's answer:
Most newsletter analytics tools are cloud-based SaaS with monthly subscriptions. StackStats is a one-time purchase that runs entirely on your device. For Substack writers who care about privacy — especially those with paid subscribers — that's a meaningful difference. You also get analytics features that don't exist anywhere else, like bot-filtered open rates and cohort retention, without having to migrate away from Substack.
StackStats.app's answer:
Serious Substack writers who are frustrated by Substack's shallow native analytics and want real data to drive growth — without moving their subscriber data to the cloud.
StackStats.app's answer:
Electron (macOS + Windows), HTML/CSS/JavaScript, Chart.js, PapaParse. Optional AI layer supports Ollama, Claude, GPT-4, Gemini, Groq, and OpenRouter. Licensing via Cloudflare Workers + D1. Payments via Gumroad.
Share your experience with using Sideline and StackStats.app. For example, how are they different and which one is better?
Recommendations tracked on public social media and blogs since March 2021.


Tracking Sideline since Mar 2021.
I'm working on 3 products now: 1. FormBeep(https://formbeep.com) at $38 MRR now - A form to Whatsapp tool. Stack is mainly CF workers with Clerk Auth. 2. SlashLink(https://slashlink.app) $0 - A simple pay as you go amazon link localizer.... - Source: Hacker News / 3 days ago
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