CalcForge records 31,360 monthly visits with -4.8% month-over-month growth and Free, Paid pricing. Spark Mail records 435,229 monthly visits with -13.5% growth and Freemium, Free Trial pricing.
Open-source engineering calculators for civil and structural design
Smart, focused email with AI help — for individuals and teams
| Dimension / Metric | | |
|---|---|---|
| Official Domain | calcforge.com | sparkmailapp.com |
| Pricing Model | Free, Paid | Freemium, Free Trial |
| Monthly Visits | 31.36K (31,360) | 435.23K (435,229) |
| MoM Traffic Delta | -1.56K (-4.8%) | -67.76K (-13.5%) |
| Primary Market & Share | 🇮🇳 India (16.1%) | 🇺🇸 United States (31.3%) |
| Direct Visits / mo | 12.46K | 198.43K |
| User Rating | 4.3 | 4.3 |
| Supported Platforms | Website | Website |
Open-source engineering calculators for civil and structural design
Structural, geotechnical, tunnelling and contractor tools available free and open source on GitHub.
Searchable construction datasets covering high-rise buildings, bridges, tunnels, dams and housing.
Registered users get calculation workings, bending/shear/deflection diagrams and PDF export.
Four project-based pathways in Python, AI for construction, AI governance and building AI agents.
Smart, focused email with AI help — for individuals and teams
Spark's Smart Inbox and Priority highlight messages from important people and bundle newsletters and notifications so the rest of your inbox stays quiet.
An AI Assistant lets you find, summarize, and take action on anything in your inbox, while an AI writing assistant drafts emails and Auto-Drafts pre-writes replies.
Translate incoming messages, get instant summaries of long threads, and quickly grasp the point without reading every line.
Share drafts, leave private comments, delegate ownership, and track progress on email threads with your colleagues.
Blazing-fast keyboard-driven email experience with powerful AI features, but operates on a much higher subscription price point.
Blazing-fast keyboard-driven email experience with powerful AI features, but operates on a much higher subscription price point.
Significantly stronger team collaboration features with shared inboxes and internal chat, but less focus on standalone consumer AI drafting.
Significantly stronger team collaboration features with shared inboxes and internal chat, but less focus on standalone consumer AI drafting.
Free / Open-sourceSearch and study millions of public SKILL.md agent skills
Free / Open-sourceSearch and study millions of public SKILL.md agent skills
Provides cross-platform support with integrated AI drafting, but lacks some of Spark's advanced shared team workspace features.
Provides cross-platform support with integrated AI drafting, but lacks some of Spark's advanced shared team workspace features.
Free / Open-sourceFree practical deep learning courses, research and open-source libraries
Free / Open-sourceOpen-source database of AI models, prices and capabilities
Free / Open-sourceOpen-source database of AI models, prices and capabilities
Offers deeper AI-driven inbox organization and automated bundles, but has a different interface and navigation structure than Spark.
Offers deeper AI-driven inbox organization and automated bundles, but has a different interface and navigation structure than Spark.
Free / Open-sourceFree open course for prompt engineering and AI security
Free / Open-sourceFree open course for prompt engineering and AI security
SpecialistOne AI assistant that works wherever you work
SpecialistOne AI assistant that works wherever you work
Transforms traditional email threads into conversational chat interfaces, but requires adjusting to a non-standard inbox layout.
Transforms traditional email threads into conversational chat interfaces, but requires adjusting to a non-standard inbox layout.
Free / Open-sourceOpen-source and self-hostable AI email assistant focused on blocking cold emails and sorting, but lacks a full native mobile app client.
Free / Open-sourceOpen-source and self-hostable AI email assistant focused on blocking cold emails and sorting, but lacks a full native mobile app client.
SpecialistIndependently scored open-source alternatives to paid SaaS
SpecialistIndependently scored open-source alternatives to paid SaaS
