App Overview

Extreme Calendar icon

Extreme Calendar

Birdsoft LLC · Business

one of the most powerful calendars on ios

$7.99 · In-app purchases

PRICE
$7.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
4.3
24 ratings · Top 30%

Evidence scope: No current overall US chart position is available. Category-chart positions shown in discovery are a separate scope. Revenue is a directional model estimate, not verified earnings.

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Build Kit

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A product spec, screen plans, and build steps for your coding agent.

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What's included17 files

A product spec, phased build plan, differentiation notes, and screen references.

  • START_HERE
  • AGENTS
  • EVIDENCE
  • SPEC
  • BUILD_PLAN
  • DIFFERENTIATION
  • skills/
  • screens/
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Illustrative example: an invoice app for independent contractors. Your kit is tailored to the app you choose; this is not its generated content.

Feature spec

Goal: Send a clear invoice after finishing a job.

  • Add a client, line items, a due date, and payment instructions.
  • Preview the total before exporting a PDF.
  • Keep an editable draft if export fails.

Screen plan

Invoice editor: Client at the top, editable line items in the middle, total and preview action at the bottom.

States: Empty draft, validation errors beside each field, exporting, and a retry action that preserves the draft.

Differentiate and validate

Hypothesis: Contractors need faster repeat invoices more than more templates.

First experiment: Test duplicating a previous job with five contractors. Watch where they hesitate before expanding the feature set.

The full kit adds a phased build plan, evidence notes, tool prompts, and implementation guidance. It is a plan for your coding agent, not a finished app.

Usage: Mechanics are fair game; never reuse the original name, branding, assets, or verbatim copy.

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Quick prompt

> SELECT BUILD PLATFORM:

Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.

// RORK SYSTEM PROMPT
Rork plan preview for Extreme Calendar: map the core Business workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
            

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Opportunities

AI-GENERATED OPPORTUNITY HYPOTHESES

These are generated suggestions, not verified review quotations. Check current App Store reviews and speak with users before treating a possible gap as a requirement.

Hypothesis 1

Provide more customizable settings for event reminders and notifications.

Assumption to check: Limited customization options for events

Validate with people who use this workflow before building.

Hypothesis 2

Add features for sharing calendars or events with others.

Assumption to check: No collaborative features

Validate with people who use this workflow before building.

Hypothesis 3

Enhance the UI with themes and color options for events.

Assumption to check: Lack of visual appeal in calendar view

Validate with people who use this workflow before building.

Hypothesis 4

Optimize app performance for lower-end devices.

Assumption to check: Inconsistent performance on older devices

Validate with people who use this workflow before building.

App evidence

Original App Store material. Ratings and screenshots describe the existing app, not proof of demand for your version.

App Store description

one of the most powerful calendars on ios. advanced views with plenty of options all designed for speed and flexibility. you wont get this much information at a glance from any other calendar, and adding events in-line allows you to get in and out and on with your busy day. based on extreme agenda, it gives you the powerful calendar based views you want at a low price, and allows you to purchase the other features of the full organizer once you need them. features include: great calendaring • powerful views including year, month, week, upcoming agenda list, and day. • pull birthdays and anniversaries from your contacts with pictures. • advanced repeating event options. • move/copy events • military time, iso week, and week start options. • uses and expands on your native calendar data. • sync like you would with the default calendar(google, icloud, exchange). • next month preview option on month view • uses time bars and icons to keep you informed at a glance • put event text right on calendar • filter events based on ical calendars. • almost 200 professional icons to mark your events • natural language entry • event templates • email events • drag-n-drop events power and flexibility • universal support • textexpander support • portrait and landscape support. • retina and iphone 5 display support. • background and color theme choices. • help system • easily upgraded to extreme agenda planner --------------------------------------- inapp purchase when you are ready to upgrade just pay the difference and your extreme calendar becomes extreme agenda. doing so adds powerful contact, task, note, and list views along with search, weather, private filtering, a status coloring choice, and over 800 more icons. and it adds categories for coloring, icons, and advanced filtering. otherwise if you want it all now, look for 'extreme agenda' in the appstore. ------------------------------------- interface you can tap-h-hold in the main calendar days and in the time area of the timeline day view for an 'add and paste' toolbar. copy/move, used with the paste, are in the toolbar on each event in timeline day. ------------------------------------- tech support / reviews please email us with feature suggestions, bug reports, or you can't figure something out instead of using the reviews if you are rating low, its not good practice to get what you want. or find extreme agenda on facebook or give @birdsoft a shout out on twitter and let us know there! we address most problems reported right away if they really are problems and will help you find a solution. we also list known problems on our site and how they are being resolved. if you like the app and it works fine for you and/or we worked to get in the features you requested please leave a review to let people know. we're working hard to give you everything you want in a calendar. -------------------------- get organized. go extreme!

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Screenshots

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Build scope

Plan a focused first version with your coding agent. These are planning assumptions, not a delivery guarantee.

Define the first version

Choose one audience and one core workflow. Use the kit to agree on its screens, data, and acceptance criteria before building.

Set boundaries

Decide which secondary features, integrations, and platform support can wait. Your version does not need to reproduce everything in the original.

Check the hard parts

Validate external services, specialist technology, data access, and ongoing costs for your chosen scope.

SUGGESTED BUILD STACK
React Native
Expo
react-navigation
@react-native-async-storage
expo-calendar
date-fns
BUILD KIT DIFFICULTY
Intermediate

From the Build Kit assessment.

A reliable timeline needs an agreed scope and a technical check. Ask your agent to estimate the phases in BUILD_PLAN.md after that review.